Reversing connector plug and adapter for three-phase motors



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April 7, 1953 J J. ROBINSON, JR ErAL 2,634,344

REVER'SING CONNECTOR PLUG"AND ADAPTER RoR THREE-PHASE MOTORS Filed Jan. l0, 1951 2 SHEETS--SHEET 2 Snventors Joseph J. Robnsondn @ai Bu Halo ard M Wa ssem am Gttornegs Patented Apr. 7, 1953 REVERSING CONNECTOR PLUG AND ADAPTER FOR THREE-PHASE MOTORS Joseph J. Robinson, Jr., Dover, and Howard M. Wassern, New Philadelphia, Ohio Application January 10, 1951, Serial No. 205,344

The invention relates generally to. electrical connecting devices or connector plugs for use with eXible electric cords, adapted for insertion into electrical receptacles or sockets, and more particularly to a device of this character in the rform of a reversible, connector plug or adapter, especially designed for connecting a three-phase motor.

Such terminals or connector plugs for use in a three-phase line are provided with three prongs, or plug-in points,A arranged for insertion, in one position only,' into a conventional three-phase receptacle or socket.

' In shops or factories where three-phase motors are used, it is customary' practice for employees, oftheshop or factory, to dothe wiring of the motors themselves, connecting the three wires from the motor to the cord terminal or connector plug, and it frequently happens that after the wiring has been completed, it is found that the wires are connected to the wrong prongs or plug in points of the cordvterminal or connector plug, Vcausing the motor to run in reverse. This requires that the terminal or connector plug be taken apart and the connections of the wires changed. y

The present invention contemplates the provision of Aa connector plug or adapter comprising two-membersrotatably connected together, one member carrying the prongs, or plug-'in points, for insertion into a conventional three-phase receptacle or socket, and the other member being connected to the wires leading to the motor.

Another object of the invention is to'provide such a three-.phase reversing plug or adapter wherein the two members thereof are rotatabhT connected together by a central conductor which is connected to one of the wires leading to the motor and to one of the prongs or plug-in points.

A further object is to provide a three-phase connector plug or adapter of this type in which the other two prongs or plug-in points are connected to contacts carried by one member of the plug, and the other two wires are connected to contacts carried by the other member of the plug, whereby a half-rotation of one member relative to the other will reverse the engagement of the contacts.

YA still further object of the invention is to provide a connector plug or adapter of this characterhaving spring means for normally urging the two members of the plug away from each other so as to cause the contacts of the two members to tightly engage each other.

Another object is to provide a novel construc- 9 claims. (ci. zoo-51.07)

ell

tion of interengaging contacts upon the two members of the plug or adapter.

The above objects together with others which will be apparent from the drawing and .following description, or which may be later referred to, may be attained by constructing the improved connector plug or adapter in the manner hereinafter described in detail and illustrated in the accompanying drawing, in which;

Figure l is a side elevation of a three-phase reversing plug embodying the invention, with parts broken away for the purpose of illustration;

Fig. 2 a transverse section through the connector plug, taken as on the line 2--2, Fig. 1;

Fig. 3 a transverse section through the connector plug, taken as on the line 3-3, Fig. l

Fig. 4 a bottom plan view of the improved conhector plug, showing the arrangement of the prongs, or plug-in points, for insertion into a conventional three-phase receptacle or socket;

1Eig. 5 an enlarged, Ifragmentary, detail elevation showing the novel construction of the contacts upon the two members of the plug;

Fig. 6 a side elevation, partly in section, showing the invention in the form of an adapter, with a conventional three-phase connector plug detachably connected thereto;

Fig. '7 a transverse, sectional view of the adapter, taken as on the line 1 1, Fig. 6; and

Fig. 8 an exploded, perspective view of the adapter shown in Figs. 6 and 7, and the conventional, three-phase connector plug detached therefrom. The improved connector plug, as shown in Figs. l to 5 inclusive, comprises the upper and lower members indicated generally at Iii and II respectively. Each member of the connector plug may be of any conventional construction, and for the purpose of illustration the two members are shown as comprising metal shells I2 and I3 respectively, filled with any suitable insulation material, as indicated at I l and l5 respectively.

The upper member I!! of the connector plug may have an annular channel portion IE formed upon the lower edge of the metal shell I2 to receive the annular flange Il formed at the upper edge of the metal shell I3 of the lower member i I, so as to connect the two members of the plug together in such manner that they are rotatable relative to each other.

A central conductor, in the form of a rod I8 of copper, bronze or other suitable conductor material, may be xed within the center of the insulation material I5 of the lower member II of the connector plug and connected as indicated at I9 to the prong or plug-in point 2e, which is the two members of the plug. This spring urgesV the members I!) and l! apart, the flange I1 and channel I of the shells of the two members limiting the separating movement thereof.

Prongs 24 and 25 are also embedded in the insulation of the lower member II of the plug and extend through the bottom thereof, as best shown in Figs. l and 4. The prong 24 is connected, as at 2li, to a contact 21 and the prong 25 is connected, as at 28, to a similar contact 29.

- The'contacts 2l and 29 are embedded in the insulation l5 of the lower member of the connector plug and project through the top thereof.

YEach of these contacts 21 and 29 has notches 30 on opposite sides thereof, said notches being preferably substantially V-shape as shown in Fig. 5.

Contacts 3l and 32 are embedded in the insulation of the upper member Ill of the connector plug and projected down through the bottom thereof. Each of the contacts 3i and 32 has V- shape projections 33, on opposite sides, for en- Vgagement with either of the notches 3!) of the contacts 2 and 29.

The contact 3l is connected to one wire 34 of the flexible cord 35 which leads to the motor, the

contact 32 is connected with another wire 36 of said flexible cord and the upper end of the central conductor I8 is connected to the third wire 37.

With the parts in the position shown in the drawing, the wire 3l is connected to the prong 2G, the wire 34 is connected through the contacts 3l and 2'! to the prong 24 and the wire 36 is connected through the contacts 32 and 2S to the prong 25.

The prongs 2i), 24 and 25 of the connector plug may be inserted into a conventional three-phase receptacle or socket, with the parts in the position shown in the drawings. If it is found necessary to reverse the wiring, in order to reverse the direction of the motor, it is only necessary that the upper member I of the connector plug be given a one-half turn, relative to the lower member I I, withdrawing the contact 3l from vthe contact 2'! and moving it into engagement with the contact 2S of the lower member, while at the same time the contact 32 of the upper member is withdrawn from said contact 29 of the lower member and moved into engagement with the contact 2l of the lower member, thus reversing the connection of the wires 34 and 36 relative to the prongs 24 and 25 so as to reverse the motor.

It will be evident that with the contacts of the upper and lower members in either engaged position, the coil spring 22, urgingthe members I0 and I I apart, will urge the contacts of the upper and lower members into tight engagement with each other so as to make good electrical connections therebetween.

With this construction of the connector plug, it will be seen that it is immaterial how the wires may be connected as it is only necessary to give the members of the connector plug a half-revolution relative to each other in order to reverse the connection.

Referring now more particularly to Figs. 6, 7

and 8, in which the invention is illustrated as embodied in an adapter plug arranged to be plugged into a conventional three-phase receptacle or socket, and to have a conventional threephase connector plug attached thereto, the device is shown as comprising the upper and lower members indicated generally at IIJa. and I la.

The two members are shown as comprising metal shells I2a and I3a, filled with insulation material, as indicated at I4a and i5a. The upper member Illa, of the adapter, is shown provided with an annular channel portion Ia formed upon the lower edge of the metal shell |2a to receive the annular flange Ila, formed at the upper edge of the metal shell I3a of the lower member IIa, so as to connect the two members of the adapter together in such manner that they are rotatable relative to each other.

A central conductor, in the form of a rod |811,

'of copper, bronze or other suitable conductor material, may be fixed within the center of the insulation material I5a, of the lower member Ila, and connected, as indicated at lc, to the prong or plug-in point 28a carried by the lower member IIa and projecting downwardly and outwardly therefrom.

The upper portion of the conductor rod ISa is rotatably received within a suitable opening 21a, formed in the insulation I4a of the upper member Ia of the adapter. l

A coil spring 22a surrounds the contact rod 48a, in spaced relation thereto, and opposite ends thereof are received in the annular groove 23a formed in the opposed faces of the insulation |4a and I 5a of the two members of the adapter.

Prongs 24a and 25a are also embedded in the insulation I5a, of the lower member I la, and extend through the bottomy thereof as shown in Fig. 6. The prong 24a is connected as at 26a to a contact 27a and the prong 25a is connected, as at 28a, to a similar contact 29a.

The contacts 21a and 29a are embedded in the insulation I5a, of the lower member I I a, and project through the top thereof. Each of these contacts has notches 30a on opposite sides thereof and identical with the notches 35 shown in Figs. 1 and 2.

Contacts Sla, and 32a are embedded in the insulation I4a, of the upper member Illa of the adapter, and project down through the bottom thereof, veach of these contacts having V-shape projections similar to the projections 33 in Figs. 1, 2 and 3, for engagement with either of the notches 30a of the contacts 21a and 29a.

The contact Sla is connected to a pair of spring contact jaws 4 I, and the contact 32a is connected to a similar pair of spring contact jaws 42, these jaws being located in slots 43 and44 respectively, opening through the top of the insulation I4a of the upper member lila.

A similar pair of spring contact jaws 45 is located in Ya slot 46 in the insulation |40., and is rotatably connected to the center post I 8a as by a conductor 41.

A conventional three-phase connector plug 48' may be detachably connected to this adapter. This connector plug has three prongs projecting from its lower side, and designated by the numerals 48, 49 and 50. The prong- 48 is connected to one wire 34a of the exible cord 35a, which may lead to a motor or the like, the prong 49 is connected to the wire 36a of said` cord, and the prong 58 is connected to the wire 31a of said cord.

The prongs 20a, 24a and 25a, of the adapter, may be plugged into a conventional three-phase receptacle, andthe prongs .48, 49 and 59 of the conventional three-phase connector plug may be plugged into the contact jaws M, 42 and 45 respectively of the adapter.

With the parts in the position shown in Fig. 6 of the drawings, the wire Sla is connected through the prong 5E), contact jaws d5, conductor 4'1, center post -13a and conductor 19a tothe prong a, the wire 315:1 is connected through the prong 48,contact jaws A. i contacts .3io and Zia and conductor 26a to the prong 24a, and the wire 35a is connected through the prong 48, contact jaws 42, contacts 32a and 29a, and `conductor 28a to the prong a.

If it is found necessary to reverse the wiring, in order to reverse the direction of the motor, lit is only necessary that the upper member 10a of the adapter be given a one-half turn, relative to the lower member, withdrawing the contact 31a from the contact 21a and moving it into engagement with the contact 29a of the lower member, while at the same time the contact 32a of the upper member is withdrawn from said contact 29a of the lower member and moved into engagement with the contact 21a of the lower .v

member, thus reversing the connection of the wires 34a and 36a relative to the prongs 24a and 25a so as to reverse the motor.

We claim l 1. 4A reversing adapter plug for a three-phase line, comprising a pair of members, annular channel and flange means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member, a multiconductor cable having three conductors there- -f in, one of said conductors being connected to one prong, said one conductor forming a pivot around which the members rotate a-diametrlcally spaced pair of contacts in said one member, means connecting each of the other two prongs to one of said contacts and a diametrically spaced pair of contacts in the other member for engagement with the first named contacts, each of the second named contacts being connected to one of the other two conductors, one pair of said contacts having notches in opposite sides, the other pair of contacts having projections on opposite sides for engagement in said notches.

2. A reversing adapter plug for a three-phase line, comprising a pair of members, annular channel and flange means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member, a multiconductor cable having three conductors therein, one of said conductors being connected to one prong, said one conductor forming a pivot around which the members rotate a diametrcally spaced pair of contacts in said one member, means connecting'each of the other two prongs to one of said contacts and a diametrically spaced pair of contacts in the other member for engagement with the first named contacts, each of the second named contacts being connected to one of the other two conductors, one pair of said contacts having notches in opposite sides, the other pair v of contacts having projections on opposite sides for engagement in said notches, and spring means urging the members apart, whereby said projections will be tightly engaged in said notches.

3. A reversing adapter plug for a three-phase line, comprising a pair of members, annular channel and flange means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member, a centrally located conductor rod pivotally connecting the members together, means connecting said rod to one of said prongs, a multi-conductor cable having three conductors therein, one of said conductors being connected to said rod, a diametrically spaced pair of contacts in said one member, means connecting each of the other two prongs to one of said contacts and a diametrically spaced pair of contacts in the other member for engagement with the rst named contacts, each of the second named contacts being connected to one of the other two conductors, one pair of said contacts having notches in opposite sides, the other pair of contacts having projections on opposite sides for engagement in said notches.

4. A reversing adapter plug for a three-phase line, comprising a pair of members, annular channel and flange means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member, a centrally located conductor rod pivotally connecting the members together, means connecting said rod to one of said prongs, a multi-conductor cable having three conductors therein, one of said conductors being connected to said rod, a diametrically spaced pair of contacts in said one member, means connecting each of the other two prongs to one of said contacts and a diametrically spaced pair of contacts in the other member for engagement with the nrst named contacts, each of the second named contacts being connected to one of the other two conductors, one pair of said contacts having notches in opposite sides, the other pair of contacts having projections on opposite sides for engagement in said notches, and spring means urging the members apart, whereby said projections will betightly engaged in said notches. Y

5. A reversing adapter plug for a three-phase line, comprising a pair of members, annular channel and ange means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member, a multiconductor cable having three conductors therein, one of said conductors being connected to one prong, said one conductor forming a pivot around which the members rotate a diametrically spaced pair of contacts in said one member, means connecting each of the other two prongs to one of said contacts and a diametrically spaced pair of contacts in the other member for engagement with the rst named contacts, each of the second named contacts being connected to one of the other two conductors, one pair or said contacts having V-shape notches in opposite sides, the other pair of contacts having V-shape projections on opposite sides for engagement in said notches.

6. A reversinsr adapter plug for a three-phase line, comprising a pair of members, annular channel and dang@ means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member, a centrally located conductor rod pivotally connecting the members together, means connecting said rod to one of said prongs, a diametrically spaced pair of contacts in said one member, means connecting each of the other two prongs to one of said contacts, a diametrically spaced pair of contacts in the other member for engagement with the rst named contacts, spring contact jaws connected to each of the contacts in said other member, one pair of said contacts having notches in opposite sides, the other pair of contacts having' projections on opposite sides for engagement in said notches, a third pair of spring contact jaws in said other member and means rotatably connecting said third pair of spring contact jaws with said centrally located conductor rod.

7. A reversing adapter plug for a'three-phase line, comprising a pair of members, annular channel and flange means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member, a centrally located conductor rod pivotally connecting the members together, means connecting said rod to one of said prongs, a dametrically spaced pair of contacts in said one member, means connecting each of the other two prongs to one oi said contacts, a diametrically spaced pair of contacts in the other member for engagement with the rst named contacts, spring contact jaws connected to each of the contacts in said other member, one pair of said contacts having notches in opposite sides, the other pair of contacts having projections on opposite sides for engagement in said notches and spring means urging the members apart whereby said projections will be tightly engaged in said notches, a third pair of spring contact jaws in said other member and means rotatably connecting said third pair of spring contact jaws with said centrally located conductor rod.

8. A reversing adapter plug for a three-phase line, comprising a pair of members, annular channel and flange means connecting the members together tor relative rotation, three spaced plug-in prongs carried by one member, a centrally located conductorrod pivotally connecting the members together, means connecting said rod to one of said prongs, a diametricaliy spaced pair of contacts in said one member, means connecting each of the other two prongs to one of said contacts, a diainetrically spaced pair of contacts in the other member for engagement with the rst named contacts, sprinCr contact jaws connected to each of the contacts in said other member, one pair oi' said contacts having V- shape notches in opposite sides, the other pair of said contacts having V-shape projections on opposite sides for engagement in said notchesfa third pair of spring contact jaws in said other member and means rotatably connecting said third pair of spring contact jaws with said centrally located conductor rod.

Si. A reversing adapter plug for a three-phase line, comprising a pair of members, annular channel and iiange means connecting the members together for relative rotation, three spaced plug-in prongs carried by one member', a cen'- trally located conductor rod pivotally connecting the members together, means connecting said rod to one of said prongs, a diametrically spaced pair of contacts in said one member, means connecting each of the other two prongs to one'of said contacts, a diametrically spaced pair of con tacts in the other member for engagement with the nrst named contacts, spring contact jaws connected to each of the contacts in said other member, one pair of said contacts having V-shape notches in opposite sides, the other pair of said contacts having v-shape projections on opposite sides for engagement in said notches, and spring means urging the members apart whereby said projections will be tightly engaged in said notches, a third pair of spring contact jaws in said other member and means rotatably connecting said third pair o spring contact jaws with said cenitrally located conductor rod.

JOSEPH J. ROBINSON, JR. HOWARD M. WASSEM.

REFERENCES CITED rihe following references are of record in the 

